Sander



l.. v. GRoyER SANDER May 17, 1949.

3 Sheets-Sheet 1 Filed April 4. 1947 L. V. GROVER May 17, 1949*.

SANDER 5 Sheets-Sheet 2 Filed April 4, 1947 .ZWEI-.2 Dr LY/vDo/v V. Gnoven.

L. V. GROVER SANDER :s sneets-sheet :s

Filed April 4, 1947 Ea-Ewa? gigi Patented May 17, 1949 UNITED STATES PATENT OFFICE Claims.

The present invention relates generally to a sander, and more particularly to a bench sander utilizing a narrow abrasive belt which is easily adjusted to several different positions to readily be accommodated to the particular characteristics of workpieces being sanded.

According to the present invention, the sander includes a -base member having a relatively small area of contacts with a bench. An endless belt supporting device or structure is pivoted to the base to swing in vertical direction. The belt supporting device or structure includes two long arms pivoted together adjacent similar ends, in V- shape in side elevation. Means are provided for angularly adjusting said arms to vary the distance between the other ends of the same. The other end of one arm is mounted on a pivotal connection between the base and the device while the other end of the other arm is spaced from the said other end of said one arm a distance determined by the relative angular adjustment of the two arms.

A shaft extends through the pivotal connection between the base and the belt supporting device and carries a pulley keyed to it which constitutes the driving pulley for the belt.

A second pulley is journaled in the remote end of said one arm while a third pulley is journaled in the said other end of said other arm.

An endless belt is trained about said pulleys. The construction presents a belt-supporting device or structure which is triangular in side elevation, the distance between the said other ends of said arms is short as compared to the lengths of the arms Novel means for angularly adjusting the arms are provided.

It is therefore an object of the present invention to provide a bench sander utilizing an endless belt, and embodying novel belt tension control means.

A further object of the present invention is to provide a bench sander utilizing an endless belt, with novel means for tracking the belt to prevent its displacement from the pulleys.

A further object of the present invention is to provide a sander including a belt-supporting device comprising two arms pivotally connected for scissors like action, together with novel means for angularly adjusting the arms.

Another and yet further object of the present invention is to provide a belt sander of simple construction, adapted for power operation, and having means for quick replacement of a belt in the event it becomes worn out or broken.

Another and yet further object of the present invention is to provide a sander including a beltsupporting device triangular in side elevation, and angularly adjustable about a fixed axis to thereby make any of the belt flights available for sanding work pieces.

The invention has for an additional object the provisions in a sander utilizing and endless belt, of a belt supporting device including two relatively long arms pivoted together near similar ends and arranged in elongated triangular relationship so that the apex of the triangular structure may enter inside work pieces for sanding such insides.

An additional object of the present invention is to provide a sander having a long, tapered belt-supporting structure generally triangular in side elevation with one roller at the apex end and two rollers at the base end, which two rollers are laterally spaced, an endless belt trained about said rollers, together with means whereby the belt-supporting structure mai7 be swung about an axis of one of the rollers in a vertical plane to present any of the three nights in convenient position for sanding with the selected night, together with means for securing the structure in adjusted position. "WF

An additional object of the present invention is to provide a sander of small size which may be quickly and easily adjusted to various positions for sanding various articles and in which novel means are employed for belt-tension adjustment.

The above, other and further objects of the present invention will be apparent from the following description and accompanying drawings.

A form of sander chosen to exemplify the present invention is illustrated on the accompanying drawings, and the views thereof are as follows:

On the drawings:

Figure 1 is a side elevational view of the sander showing in full lines the belt supporting structure in horizontal position and in dotted lines the belt supporting structure in vertical position;

Figure 2 is an end view of the sander looking at the left end of Figure 1;

Figure 3 is a vertical sectional view through the sander with the belt supporting structure in horizontal position and taken in the plane of line III--III of Figure 3;

Figure 4 is a fragmental sectional view taken in the plane of line IV-IV of Figure 3;

Figure 5 is a fragmental elevational view of an end of one of the arms and a roller supported by said ends, taken from the side of the arm opposite to that shown inFigure l;

Figure 6 is a side elevational view of the sander, with the belt-supporting structure in horizontal position and showing the relationship of the parts when applying a belt to or moving a belt from the belt-supporting structure, the dotted lines representing the belt in working position; and

Figure 7 is a vertical sectional view, with parts in elevation, taken in the plane of line VII-VII o'f Figure l.

As shown on the drawings:

Referring to the drawings, the illustrated sander comprises a base, designated generally as B and a belt supporting device or structure designated generally as C.

The base B is illustrated as formed* as acasting with a bottom I0, and an integral.l upstanding side member II. The side member II is formed with a cup I3 the bottom of which cup, shown as vertical in Figure 7, isiapertured at I4 centrally. of.` the cup. A\ bearin'gf plate I5'4 is formed with a cup Iz. A. balli bearing M: is. installedf in; the cup: Ilof. the side member- I2.I:, while a ball: bearing mi is installed? in. the' cup. I6 .ot thef bearingA support'. Anl arcuate'lsloull is formedi in the: side member II, while a corresponding arcuate is formed inthe sider platek I5.

Reinforcing the si'd'e'fmemberI IiI with: respect to the base I llarewebsf Illu andiels.v The bearingsupport has: an` angular.V lug 22x disposed to overlap theA web 2'fIi when: the= bearing support is in operativeposition. A screwv 231 connectsthe lug 2122 with the-Web@ I1 to holdithe bearingfsupport I5 in operative position, which is thatshown in full lines in Fig-urefl.

A- shaft. 24' is= supported@ by' the ball bearings I'I and I8?, the shaft entering: theA aperture I4' in` the cup I3= of thesidemember II- andv abuts the interior or the` bottom of the cup Ii6= ofthe bear-ing support |52. A. pulleyf 28, having a vgroove` in it is fastened tothe projecting end of theshaft byfmeans of 'aset scr-ewl 29a The pulley 2t-4 is adapted to be connected by a V'belt with a source, ofpower for actuating the sander.

The belt-supporting-deviceor-structureas herein illustrated includes two armspi-votedf together adjacent similarends; These@ arms will herein for convenience` be designated;` thev lower arm and the upper arm.

The lower arm' 30 is illustratedl as formed as a channell with a web 31|` and upstanding flanges 321 The anges 3-2- have projections 33', adjacent their outer *endsy which are aperturedv to receive a pivotpin.

The lowerl armi 30 is at its-inner end swingably mounted*Y on the base` B; Toso mount the lower arm 3U, thev inner' ends of its flanges are enlarged and apertured to surroundV the ange I3a ofthe cup` lf3, and theii'ange ISa.- of the cup I6 ofthebearing support` I5, as illustrated in Figure 7. As` may be observed inV4 Figure 3; the web 3I of the lower arm- 311K is. notcofextensive with the anges, but-.stops shortv ofthe .ends of` the` flanges, and may be apertured as atflfa,v to reduce weight. The flanges 32 at. the.` outer end 35 ofthe lower arm 3u are apertured' to; receive a pin 3b as a support for apull'eyfl. The pitt 36u-Ilias` take theform of a square-headed bolt'in which event there will be a nuten theother end of a bolt.

The upper arm 38; is; illustrated asY formed as a channel memberwith at 'web :39, andV alges 4t', which angesvdepend ,trom thel web 9, as shown. in Figure 3,Y that; isA Vattend, toward the flanges 32 of the lower arm 3B. The width of the upper arm 38 is less than the width of the lower arm 30 by an amount suflicient to enter between the projections 33 of the flanges 32 of the lower member 30, as may be noted in Figures l, 3 and 6.

The outer ends of the flanges 40 are formed with projection 4I which enter between the projections 33 of the anges of the lower arm 30. A pivot pin 42 passes through registering aperturesin the projections 33. and 4I pivotally connecting the arms 30 and 38 adjacent their outer ends. The pivot pin 42 may take the form of a bolt having a square head at one end and a nut applied to the other end to connect the two arms together in working relation.

Referring to Figures 3 and 5, it will be noted that the iianges 4E) at the inner end of the upper arm 38 are deflected from the flanges at an obtuse angle and that the web, is absent from the deected end portions of the flanges. A pulley 43 is supportedv between the. end; portions ofthe flanges 49 by a. pivot pin 4 4.

Referring toFigure 4', itv will be. noted that one of the end flanges is. designatedV as` 40a andl the other as 49h. The flange 4IIa is aperturedy to receive the pin lwith a snug't. The end flange Mib. is apertured atv 45,. thel diameterV of which aperture is greater than. the diameter of the pin 44 so that the pin may move withinl the aperture. The pin may take the form of a round-headed bolt as shown in Figure 4 wherein 44av designates the head and a nut 44h is: .applied to the other end of the bolt to hold the various parts in operative relationship.

A crank 46 is pivoted on a, screw 4l which is threaded into a suitable aperture 48v in the. end iiange 40h. They crank 46 has an arm I9A apertured at 5t tov receive the pin 44., as shown in Figure 4. Another arm 5I is. formed as a part of the crank andA is disposedf at an angle to the arm 49, as illustrated' in Figure 5, tov constitute a handle to shift the crank. By loosening the screw 4l, the crank may be oscillated on the screw as a center, which oscillationshifts the pin 44: within the aperture 45 of theflange 40h; to` thereby tilt the pin 44. When the pin has been tilted to a desired position, it isv securedI in that position by tightening the screw 4.1.

The pin carries the pulley 43, which pulley is supported on ball bearings 52 to reduce friction to a minimum. Thus, when the shait 4411s tilted as described, the-pulley 43 will be correspondingly tilted and thus serve to maintain the tracking of the endless belt which passes around the pulley in operative position and prevents its accidental moving off of one of the pulleys.

For securing the belt-carrying device or struc-- ture in desired angular .position with respect to the base, in the horizontal position shown in full line in Figure l, as well asin the Vertical position as shown by dotted line in this` gure, and in any intermediate position, screws 53 and 54 are provided. Screw 5'3; is disposed through the arcuate slot I9 in the, side member II where it is threaded into an aperture 55 in adjacent flange 32 of the lower arm. The screw 54 is disposed extending through the arcuate slot 2G .in the bearing support I5 and is threaded into a threaded aperture inthe adjacent flange 32 of the lower arm. These screws. are loosened to enable swinging of the belt supporting structure or device and tightenedA toY holding structure in desired angular position.

For relatively angularly .adjusting the lower and upper arms 30 and 38 respectively, a toggle mechanism is used. The toggle mechanism illustrated includes a link 56 pivoted at 51 to the ilanges 40 of the upper arm 38. A second toggle link 58 is pivoted at 59 to upstanding lugs 6l? shown as integral parts of the web 3l of the lower arm 30. A bolt 6l connects the adjacent ends of the links as shown. A post 62 formed integrally with the upper arm 33 extends in wardly thereof towards the lower arm and is provided with an aperture 63. An elongated bolt B4 is provided with a head 55 which is apertured to receive the pin 6 I, connecting the toggle links. A thumb screw 66 on the bolt 54 contacts the face of the post 62 which is remote from the toggle. As the thumb screw 66 is turned in one direction, the bolt 64 is moved to the left, as viewed in Figure 3, to separate the arms 33 and 33 as is obvious. When the thumb screw is rotated in the opposite direction, the bolt B4 will be moved to the right to draw the arms 33 and 38 toward each other. Manipulation of the toggle, in the manner described, will thus angularly adjust the arms 3!! and 38 to tension the endless belt which passes about the pulleys carried by said arms.

E is an endless abrasive belt passing about the pulleys 25, 31 and 43, as shown in Figure 3.

The sander of the present invention is herein illustrated as one arranged to take a belt one inch in width and approximately inches in length. This type of belt is available on the market. The endless belt is on its inside imprinted with an arrow to designate the direction of belt travel when applied to the sander.

Arrows in Figures 1 and 3 designate the direction of travel of the belt.

In order to apply an endless belt E to the sander, as illustrated, the screw 33 is removed from the lug 22 of the bearing support i5 and the screw 54 loosened. The bearing support l5 is then swung in clockwise direction from the operative position shown in Figure 1 to the inoperative position shown in Figure 6. The toggle is then manipulated to move the upper arm 38 toward the lower arm 33, a distance sufficient so that the belt E may be applied about the pulleys 43 and 25 and then about the pulley 31. When the belt has been applied as directed, the bearing plate l5 is returned to normal position, which is that shown in Figure l, and the screw 23 inserted to fasten the bearing support l5 to the web 2| of the base. The toggle mechanism is then manipulated to move the upper arm 38 away from the lower arm 3i) a distance sufficient to impose proper tension on the belt E.

Should the belt break or wear out, it may be removed as described and a new one substituted.

Referring to ,Figure 3, it will befobserved that the web 39 of the upper arm` 33 serves as backing or platen underlying the night of the belt between the rollers or pulleys 31 and 33.

There are two work supports shown in the drawings, one of them, 61, is carried by the upper arm 38 and the second of them, 63, is secured to the base B` The work support 61 may be formed as a casting or stamping and includes a platform 69 which spans the belt in the flight between the rollers 31 and 43, with its lower margin spaced from the belt, as clearly shown. The work support 61 is pivoted to one of the flanges 40 of the upper arm 38 by a suitable pivot 1G which may be in the form of a screw. The side portion of the work support is preferably formed with an arcuate arm 1| having an arcuate slot 12 in it. A bolt 13 projects through a suitable aperture in the portion 4Gb of one of the side flanges of the upper arm 33 and through the slot 12. Inwardly of the arm 1l a nut 14 is threaded onto the bolt 13 to tighten or loosen it with respect to the arm 1l. When loosened the work support S1 may be adjusted about the pivot 10, and when tightened holds the Work support in an adjusted position with respect to the arm 38. Removal of the pivot pin 1G and the bolt 13 enables removal of the work support 61 from the arm if occasion for so doing should arise.

The work support 68 is removably attached to the base B by means of a screw 15 passing through a suitable aperture in the work support and threaded into the side member H of the base, as shown in Figure 3. The table 13 of work support 68 has a horizontal surface adjacent the ight of the belt between the rollers :23 and 25.

When the belt-supporting device or structure is swung from the full line position of Figure 1 to the dotted line position it is, of course, necessary to remove the work support 38 from the base.

When the belt-supporting device or support is in a horizontal position, that is the position shown by full lines of Figure 1, the night of the belt between the rollers 31-43 or rollers 43-25 may be utilized for sanding purposes., A work piece might be held in contact with the belt overlying the web 39 of the upper arm 38, and resting against the work support 61, for sanding a surface of said work piece.

A work piece might be supported on the table 16 of the work support 68 and sanded by the flight of the belt between the rollers 43 and 25.

When it is desired to utilize the flight of the belt between the rollers 25 and 31, then the beltsupporting device or structure would be moved to substantially vertical positions, as shown by dotted lines in Figure 1.

After the belt E has been applied about the rollers 43, 25 and 31, in the manner heretofore described, and the belt tightened by manipulation of the toggle, the sander is ready for use.

In operating the sander of the present inven tion, the operator determines what one of the three ights of the belt Will be used. With the belt-supporting structure or device in horizontal position, that is the position shown in full length in Figure l, the operator may use either of two flights of the belt, that is the ight between the pulleys and rollers 31-43 or the flight between the pulleys or rollers 4.3-25.

When it is desired to sand the inside of work pieces the belt-supporting device or structure may be moved to elevated position, and the piece fitted over the apex of the device or structure whereupon the operator may utilize the flights between the rollers 31-43 or the flight between the rollers 25-31. It is quite apparent that a work piece being sanded on the night between the rollers 25-31 slight pressure must be used as otherwise there might be the probability of breaking the belt. When sanding against the flight of the belt between the rollers 31-43 greater pressure may be applied as this flight of the belt is for the major portion of its length supported or backed -by the web or platen 39 of the upper arm 38.

During the operation of the sander, if per chance the belt loosens, then the tension may be increased by proper manipulation of the toggle.

andai-.5

7 The tiltable support of the roller or pulley 43. makes it possible to maintain the tracking-10ir the belt evenly over the several rollers or pulleys. The belt engaging surfaces of the roller are crowned slightly to prevent any tendency of the belt to run off of any of the rollers while in use, and also for effecting better driving relation between the belt and pulleys.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of theappended claims.

I claim as my invention:

1. A sander including two arms pivotedv together adjacent similar ends, means connecting said arms to relatively adjust them with scissors-like action, pulleys` on said arms, an endless belt trained about said pulleys, and means carried by one of said arms underlying said belt to provide a backing surface for the belt, said adusting means including two toggle links connected.l together at similar ends and` at their other ends pivotally connected respectively tol said arms, a bolt connected at one end to the pivotal connectionv of said links to eachother, a` support as av part of one arm receiving said bolt and means threaded on said bolt and bearing against said support to eiiect movement of the pivotal connection of said links towards and away from said support to thereby vary the angular adjustment ofsaid arms.

2. A sander including twoy arms of substantially equal length pivoted together adjacent similar ends, means connecting said arms to` relatively adjust 'them with scissors-like action,.pulleysv on said arms,` work supporting means carried. by said arms, and an endless belt trained about said pulleys, said adjusting means controlling the tension of said belt, said adjusting means includingl two toggle links connected together at similar ends and at their other ends pivotallyconnected respectively to'said armsa bolt connected. at oneend to the pivotal connection of said linkstoieach other, a support asa' part ofy one arm: receiving said boit and means threaded on said bolt and bearing against said support to effect movement of` the pivotal connection of said' links towards and away-from said support to thereby-vary the angular adjustmentv of said arms.

3. A supporting structure for anv endless belt comprising two arms of substantially equallength pivoted together adjacent similar ends, three pulleys on said arms for receiving any endless belt,` anendless belt trained about saidV pulleys, means for angularly adjusting said armsto'tensionthe belt, a base supporting'said device, and mea-nsior driving one of said pulleys tomove the belt, one

of said arms underlying said endless belt toprovide a Work support said adjusting means including two links connected together at similar ends and at their other ends pivotally connected respectively to said arms, a bolt connected at one end of the pivotal connection4 of said links to each other, and a support as a part of one arm receiving said bolt and a wing nut threadedv on said-.bolt and bearing against said' support whereby as the nut is rotated it will move thepivotal' connection of said links relative to saidsupport' to thereby vary the angular adjustment of said-arms. 4. In a sander, a supporting devicefor an 8; endless belt comprising two arms of substantially equal length pivoted together adjacent similar ends and movable towards and away from each other with scissors-like action, pulleys on said arms, an endless belt trained about said pulleys, and means for angularly adjusting said arms including two links connected together at similar ends and at their other ends pivotally connected respectively to said arms, a bolt connected at one end of the pivotal connection of said links to each other, a support as a part of one arm receiving said bolt and a nut threaded on said bolt and bearing against said support whereby as the nut is rotated-it will move the pivotal connection of said links toward and away from said support to thereby vary the angular adjustment of said arms and the tension of said belt.

5. A sander including a base, an endless belt carrying device pivotally connected to said base and including two arms pivotedl together about an axis remote from the pivotal connection of said device to said base, means connecting saidl arms to eiect scissors-like action of the same, pulleys on said arms, a driving pulley mounted Ion said pivotal connection of the device to the base, means for driving said last mentioned pulley, and an endless abrasive belt trained about said pulley, said arms, pulleys and belt cooperating to define three separate belt flights, said connecting means including two links connected together at similar ends and having their other ends pivotally connected respectively* to said arms, a bolt con nected at one end to the pivotal connection of said.

links to each other, and a pivot as a part of one arm receiving said bolt and anut threaded on said bolt and bearing against said pivot, whereby movement of the pivotal connection of said links relative to said support is effected by rotation of said nut to thereby control the tension of the beltwith respect to the pulleys, said arms, pulleys and connecting means being pivotable about said shaft through an arc of approximately so that eachone of said belt flights may be employed inA a horizontal, vertical or intermediate position.

LYNDON V. GROVER.

REFERENCES CITED The following references are of record in the rile of this patent:

UNITED STATES PATENTS Number Name Date 266,257 Hanson et al Oct. 17, 1882 398,497 Currier Feb. 26, 1889 462,185 Wilson et al Oct. 27, 1891 681,636 Furber Aug. 27, 1901 747,699 Gough Dec. 22, 1903 894,851 Oakley Aug. 4, 1908 1,042,354 Kroeze Oct. 22, 1912 1,049,214 Drury Dec. 31, 1912 1,191,045 Verwer July 11, 1916 1,356,338 Clarke Gct. 19, 1920 1,589,196 McCarty June 15, 1926 1,621,931 Johnson Mar. 22, 1927 1,635,399 Fischer July 12, 1927 1,701,814 Maddox Feb. 12, 1929 1,749,898 Ward Mar. 11, 1930 2,282,658 Knesley May 12, 1942 FOREIGN PATENTS Number Country Date 616.303 Germany Julv 25. 1935 

